I guess it is just something people like, similar to art. It appeals to some, not to others. I would, maybe, pay a slight premium for consecutive numbered Colt SAA's, but that is about it. When Cimarron Firearms first offered their 7th Cavalry Colt clone, I called and asked if it was possible to get a set of consecutive numbers. The gent who answered, I think it was the owner, said no problem, charged my card the same amount as if they were not consecutive and they arrived at my FFL a few days later. If he would have said there was an upcharge, probably wouldn't have done it. Several years ago, a seller by the name of George Wimer, listed 3 early M29's (don't remember if they were a dash number or not) with consecutive numbers. Can't remember the asking price, but I think it was a few thousand more than if you bought them separately. I remember them being on his website for a long time.